Redoubt volcano unlikely to have a major climate impact

Alaska's Redoubt Volcano continues to erupt, with the latest blast coming just after midnight Eastern time (7:41pm AKDT). The latest eruption threw ash 50,000 feet into the air, but the ash has settled to the ground and the ashfall advisory for cities to the north and northwest of Anchorage such as Talkeetna has expired. Redoubt is located about 100 miles southwest of Alaska's most populous city, Anchorage. The prevailing southerly winds deposited a swath of ash about 200 miles long to the north of the volcano (Figure 1). Redoubt last erupted between December 1989 - April 1990, and its ash clouds presented a major hazard to aviation. On December 16, 1989, Redoubt's eruption spewed ash into the air to a height of 14,000 m (45,000 ft) catching KLM Royal Dutch Airlines flight 867, a Boeing 747 aircraft, in the plume. All four engines stalled and the aircraft plummeted 13,000 feet before the pilot was able to restart the engines and land safely in Anchorage. The total costs to the aviation industry from the 1989 - 1990 eruption were about $100 million. Eighty percent of these costs were due to damaged equipment. For more information on the Redoubt eruption, check out the Alaska Volcano Observatory home page.

Redoubt's effect on the climate should be minimalMany historic volcanic eruptions have had a major cooling impact on Earth's climate. However, Redoubt is very unlikely to be one of them. To see why this is, let's examine recent volcanic eruptions that have had a significant cooling effect on the climate. In the past 200 years, Mt. Pinatubo in the Philippines (June 1991), El Chichon (Mexico, 1982), Mt. Agung (Indonesia, 1963), Santa Maria (Guatemala, 1902) Krakatoa (Indonesia, 1883), and Tambora (1815) all created noticeable cooling. As one can see from a plot of the solar radiation reaching Mauna Loa in Hawaii (Figure 2), the Mt. Pinatubo and El Chichon eruptions caused a greater than 10% drop in sunlight reaching the surface. The eruption of Tambora in 1815 had an even greater impact, triggering the famed Year Without a Summer in 1816. Killing frosts and snow storms in May and June 1816 in Eastern Canada and New England caused widespread crop failures, and lake and river ice were observed as far south as Pennsylvania in July and August. Volcanic eruptions cause this kind of climate cooling by throwing large amounts of sulfur dioxide gas into the stratosphere. This gas reacts with water to form sulphuric acid droplets (aerosol particles), which are highly reflective, and reduce the amount of incoming sunlight.

You'll notice from the list of eruptions above that all of these climate-cooling events were from volcanoes in the tropics. Above the tropics, the stratosphere's circulation features rising air, which pulls the sulfur-containing volcanic aerosols high into the stratosphere. Upper-level winds in the stratosphere tend to flow from the Equator to the poles, so sulfur aerosols from equatorial eruptions get spread out over both hemispheres. These aerosol particles take a year or two to settle back down to earth, since there is no rain in the stratosphere to help remove them. However, if a major volcanic eruption occurs in the mid-latitudes or polar regions, the circulation of the stratosphere in those regions generally features pole-ward-flowing, sinking air, and the volcanic aerosol particles are not able to penetrate high in the stratosphere or get spread out around the entire globe. Redoubt is located near 59° north latitude, far from the tropics, and thus is unlikely to be able to inject significant amounts of sulfur aerosols into the stratosphere. Furthermore, the previous 1989 - 1990 eruption of Redoubt (Figure 3) put only about 1/100 of the amount of sulfur into the air that the 1991 eruption of Mt. Pinatubo did, according to the TOMS Volcanic Emissions Group. We can expect the current eruption of Redoubt to be similar in sulfur emissions to the 1989 - 1990 eruption, and have an insignificant impact on global climate.

Figure 3. Amount of sulfur gases put into the air by recent volcanic eruptions. Note that the 1989 eruption of Redoubt put only 1/100 the amount of sulfur dioxide (SO2) into the air that the 1991 eruption of Mt. Pinatubo did. Image credit: TOMS Volcanic Emissions Group.

For more informationRealclimate.org has a nice article that goes into the volcano-climate connection in greater detail. One interesting quote from the article: There can be some exceptions to the tropics-only rule, and at least one high latitude volcano appears to have had significant climate effects; Laki (Iceland, 1783-1784). The crucial factor was that the eruption was almost continuous for over 8 months which lead to significantly elevated sulphate concentrations for that whole time over much of the Atlantic and European regions, even though stratospheric concentrations were likely not particularly exceptional.

scienceblog.com has an interesting article about the largest volcanic eruption of the 20th century--the 1912 eruption of Alaska's Mt. Novarupta, located in the same chain of volcanoes as Mt. Redoubt. According to a NASA computer model, Novarupta's climate-cooling aerosols stayed north of 30°N latitude, and did not cause global cooling. However, the model indicates that the eruption may have indirectly weakened India's summer monsoon, producing an abnormally warm and dry summer over northern India.

Which model OS did you all get? I assume you are happy with them. I have been looking at a few and Samsclub has them around $130 bucks or so US> My old OS is on its last leg (10 years and counting) and cannot be interfaced. This is the one Link

Yeah actually have an OS also, if you look real close you can see the station and the rain gauge. I saw your cam by the way very nice.

Which model OS did you all get? I assume you are happy with them. I have been looking at a few and Samsclub has them around $130 bucks or so US> My old OS is on its last leg (10 years and counting) and cannot be interfaced. This is the one Link

I bought two of the linksys wireless cams.. they are also indoor. I found a few websites that said you could mount them outside... if they were protected (under the overhangs, out of the rain). So far so good, they are both outside and working well.

They are ip addressable, so you can put them on a DDNS server, so anyone can see them. The links are on my blog. The weather station is the oregon scientific wireless setup.

Yeah actually have an OS also, if you look real close you can see the station and the rain gauge. I saw your cam by the way very nice.

Quoting charlottefl:Actually ended up buying a webcam, like an indoor one, it's just in a window. Figured I can save money on the cam for now maybe buy a 2nd station a little sooner.

It's a HP IM Plus I think.Decent quality for the price.

P.S. - Thanks Orca

I bought two of the linksys wireless cams.. they are also indoor. I found a few websites that said you could mount them outside... if they were protected (under the overhangs, out of the rain). So far so good, they are both outside and working well.

They are ip addressable, so you can put them on a DDNS server, so anyone can see them. The links are on my blog. The weather station is the oregon scientific wireless setup.

Good Morning......Trying to stay safe from severes weather the next three days in the Gulf and SE US is a given but it is also nice to finally get some much needed rain in the tri-state North FL/Southern AL & GA region...

Quoting BahaHurican:Morning, all. Cool and clear here in Nassau (airport is reporting 66 degrees, and it's still outside - for a change lol).

It's a pity that the rain people are getting in the Gulf coast states doesn't seem likely to head our way before the weekend. Yesterday I left my laptop open on my desk for about two hours. When I got back, the desk and the laptop were covered in a heavy layer of dust that had come in through a nearby partially open window.

Just replaced the batteries in my rain gauge. Ready for those summer rains! Whenever they decide to arrive. lol. Webcam is up and running. Tweaking a few more things and weather station #1 is complete. In the planning stages for #2. Also am pretty much finished with my blog. Would appreciate any comments.

Morning, all. Cool and clear here in Nassau (airport is reporting 66 degrees, and it's still outside - for a change lol).

It's a pity that the rain people are getting in the Gulf coast states doesn't seem likely to head our way before the weekend. Yesterday I left my laptop open on my desk for about two hours. When I got back, the desk and the laptop were covered in a heavy layer of dust that had come in through a nearby partially open window.

Additional Information====================Inertia between system pattern and true weakening is less for small sizes systems. (6H) Northwesterly vertical wind shear is obvious on the imagery. Low level circulation center is partially exposed west of the convection, which is eastward away over the southwestern part of Madagascar. Microwave (AMSU 0226z) and water vapor imageries show a drier air intrusion in the west. Izilda has tracked erratically but should track westward for the next hours, under the steering influence of the subtropical high pressures. Upper-level jet present in the southwest of the system is expected to be a limiting factor. Then the strengthening northerly wind shear (beyond 36 hrs) should weaken this small size system

BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE JACKSON MS 210 AM CDT THU MAR 26 2009 THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A * TORNADO WARNING FOR... SOUTHEASTERN SIMPSON COUNTY IN CENTRAL MISSISSIPPI... SOUTH CENTRAL SMITH COUNTY IN CENTRAL MISSISSIPPI... NORTHERN JEFFERSON DAVIS COUNTY IN SOUTH CENTRAL MISSISSIPPI... NORTHERN COVINGTON COUNTY IN SOUTHEAST MISSISSIPPI... THIS INCLUDES THE CITY OF COLLINS... * UNTIL 245 AM CDT * AT 210 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR PRENTISS... OR 17 MILES SOUTHWEST OF MAGEE...MOVING EAST AT 45 MPH. * THE TORNADO WILL BE NEAR... LONE STAR AND CLEM BY 215 AM CDT... MOUNT OLIVE BY 225 AM CDT... COLLINS BY 230 AM CDT...

068 WFUS54 KJAN 260640 TORJAN MSC127-129-260745- /O.NEW.KJAN.TO.W.0022.090326T0640Z-090326T0745Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE JACKSON MS 140 AM CDT THU MAR 26 2009 THE NATIONAL WEATHER SERVICE IN JACKSON HAS ISSUED A * TORNADO WARNING FOR... EASTERN SIMPSON COUNTY IN CENTRAL MISSISSIPPI... THIS INCLUDES THE CITY OF MAGEE... SMITH COUNTY IN CENTRAL MISSISSIPPI... * UNTIL 245 AM CDT * AT 140 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A STRONG TORNADO 7 MILES SOUTHWEST OF SANATORIUM...OR 8 MILES SOUTHWEST OF MAGEE...MOVING NORTHEAST AT 40 MPH. * THE TORNADO WILL BE NEAR... SANATORIUM BY 145 AM CDT... MAGEE BY 150 AM CDT... 6 MILES SOUTHEAST OF MARTINVILLE BY 155 AM CDT... RALEIGH BY 215 AM CDT... PINEVILLE BY 230 AM CDT... THIS IS AN EXTREMELY DANGEROUS AND LIFE THREATENING SITUATION. THIS STORM IS CAPABLE OF PRODUCING STRONG TORNADOES. IF YOU ARE IN THE PATH OF THIS TORNADO...TAKE COVER IMMEDIATELY!

i can't think of the last time we saw a squall quite like this one, both in width and intensity. i think we're all going to take a beating. you be safe,too, koritheman and southlaokie. i lived in the dfw area for awhile... i have to admit, it is quite exciting, scary and fun, all at the same time. i worry about those who are not paying attention...

Squall line still going strong. That isn't what we typically see with these -- all too often, they weaken significantly before striking the Baton Rouge metro area. Be careful, firegirl. I think you're going to get hit worse than we are.

thanks, tampa! the weather radio is on the hurricane preparedness list for this year. i borrowed one from a friend after gus and ike (you think i would have learned after katrina) and it really was the only way to know what was going on while we were off the grid - for over a week. etouffee on a bbq pit was an adventure - rice on a bbq pit was pure talent. i'm just sayin'... :)

nope... although you think i would have bought one after gustav... just my obsession with all things weather and you good folks on wunderground. wow - the wind is really ripping. that collision of south and west winds is pretty fierce.

Quoting firegirl:yeah you see the arrow pointing straight at donaldsonville? that's headed straight for me. fun times. moved the truck and brough the kayak inside... nothing to do now but enjoy the show... and pray everyone is ok!

yeah you see the arrow pointing straight at donaldsonville? that's headed straight for me. fun times. moved the truck and brough the kayak inside... nothing to do now but enjoy the show... and pray everyone is ok!